782
ACUS11 KWNS 100715
SWOMCD
SPC MCD 100715
INZ000-ILZ000-100915-

Mesoscale Discussion 1891
NWS Storm Prediction Center Norman OK
0215 AM CDT Mon Aug 10 2026

Areas affected...parts of east central Illinois...north central
Indiana

Concerning...Severe Thunderstorm Watch 550...551...

Valid 100715Z - 100915Z

The severe weather threat for Severe Thunderstorm Watch 550, 551
continues.

SUMMARY...Scattered thunderstorm activity continues to develop east
and south of the Lake Michigan vicinity, but the risk for additional
severe weather appears to be lowering enough that a new severe
weather watch is not anticipated.

DISCUSSION...Lingering convection now generally spreading across and
to the east/south of the southern Lake Michigan vicinity appears
rooted within forcing for ascent associated with
lower/mid-tropospheric warm advection.  This is downstream of a
low-amplitude short wave perturbation which is forecast to continue
across the southwestern Great Lakes region overnight.

A small clustering of storms now to the northwest of Danville IL
appears the lone activity maintaining roots near the surface, within
a boundary-layer characterized by seasonably high moisture content
including dew points in the lower/mid 70s F.  Located along a 30-35+
kt west-southwesterly 850 mb jet axis, near-surface hodographs are
characterized by large clockwise curvature supportive of updraft
rotation, though there is a weakness in flow further aloft,
particularly with south/southeastward extent from the current
position of the stronger convection.

As activity continues to develop east-southeastward into a somewhat
less moist air mass, any lingering risk for tornadoes seems likely
to diminish.  Potential for a couple of strong surface gusts may
persist, but it is not clear that this will require a new severe
weather watch.

..Kerr.. 08/10/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...IWX...IND...LOT...ILX...

LAT...LON   41248795 40488488 39988603 40538793 40848853 41248795

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN